Multirotor aircraft with an airframe and at least one wing

Abstract

A multirotor aircraft with an airframe and at least one wing that is mounted to the airframe, the at least one wing being provided with at least four thrust producing units that are arranged in spanwise direction of the at least one wing, wherein each one of the at least four thrust producing units comprises at least one rotor assembly that is accommodated in an associated shrouding, the associated shrouding being integrated into the at least one wing, wherein the associated shrouding defines an air duct that is axially delimited by an air inlet region and an air outlet region, wherein the air inlet region exhibits in circumferential direction of the air duct at least two different aerodynamic profiles.

What is claimed is: 
     
       1. A multirotor aircraft with an airframe and at least one wing that is mounted to the airframe, the at least one wing being provided with at least four thrust producing units for producing thrust in a predetermined direction, the at least four thrust producing units being arranged in spanwise direction of the at least one wing, wherein each one of the at least four thrust producing units comprises at least one rotor assembly that is accommodated in an associated shrouding, the associated shrouding being integrated into the at least one wing, wherein the associated shrouding defines an air duct that is axially delimited by an air inlet region and an air outlet region,
 the air duct being cylindrical, wherein the air duct comprises a front side duct wall, a board side duct wall, a rear side duct wall, and a star board side duct wall, wherein at least the front side duct wall and the board side and star board side duct walls exhibit different heights in axial direction of the air duct, wherein the different heights define an undulated geometry, and wherein the air inlet region exhibits in circumferential direction of the air duct at least two different aerodynamic profiles. 
 
     
     
       2. The multirotor aircraft of  claim 1 ,
 wherein the height of the board side and star board side duct walls is greater than the height of the front side duct wall, which is greater than a height of the rear side duct wall. 
 
     
     
       3. The multirotor aircraft of  claim 1 ,
 wherein the front side duct wall is connected to the board side duct wall and the star board side duct wall by means of an aerodynamically shaped transition. 
 
     
     
       4. The multirotor aircraft of  claim 1 ,
 wherein the at least one wing is provided with an aerodynamic profile, wherein a front section of the at least one wing that is located with respect to a forward flight direction of the multirotor aircraft upstream of the air duct is provided with a first aerodynamic profile that differs from the aerodynamic profile of the at least one wing. 
 
     
     
       5. The multirotor aircraft of  claim 4 ,
 wherein the first aerodynamic profile is shaped in spanwise direction of the at least one wing such as to create in sections different angles of attack of an inflow air stream flowing into the air duct in operation. 
 
     
     
       6. The multirotor aircraft of  claim 4 ,
 wherein a rear section of the at least one wing that is located with respect to the forward flight direction of the multirotor aircraft downstream of the air duct is provided with a second aerodynamic profile that differs from the aerodynamic profile of the at least one wing. 
 
     
     
       7. The multirotor aircraft of  claim 1 ,
 wherein the air outlet region is provided in circumferential direction of the air duct at least partly with a sharp corner. 
 
     
     
       8. The multirotor aircraft of  claim 7 ,
 wherein the sharp corner is implemented by a simple cut edge. 
 
     
     
       9. The multirotor aircraft of  claim 7 ,
 wherein the sharp corner is implemented by a Gurney flap or a covered Gurney flap. 
 
     
     
       10. The multirotor aircraft of  claim 1 ,
 wherein stator blades are arranged inside of the air duct, the stator blades being configured to redirect at least a portion of an inflow air stream in a predefined direction. 
 
     
     
       11. The multirotor aircraft of  claim 1 ,
 wherein at least one vortex generator is provided adjacent to the air duct for redirecting at least a portion of an inflow air stream in a predefined direction. 
 
     
     
       12. The multirotor aircraft of  claim 1 ,
 wherein the at least one wing comprises a board side half wing and a star board side half wing that are mounted to the airframe, the board side half wing being provided with at least two thrust producing units that are arranged in spanwise direction of the board side half wing, and the star board side half wing being provided with at least two thrust producing units that are arranged in spanwise direction of the star board side half wing. 
 
     
     
       13. The multirotor aircraft of  claim 1 ,
 wherein at least one front wing and at least one rear wing are mounted to the airframe, wherein the at least one front wing is provided with at least four thrust producing units for producing thrust in a predetermined direction, the at least four thrust producing units of the at least one front wing being arranged in spanwise direction of the at least one front wing, and wherein the at least one rear wing is provided with at least four thrust producing units for producing thrust in a predetermined direction, the at least four thrust producing units of the at least one rear wing being arranged in spanwise direction of the at least one rear wing. 
 
     
     
       14. The multirotor aircraft of  claim 1 ,
 wherein at least one additional thrust producing unit is provided for producing thrust in longitudinal direction of the multirotor aircraft in operation, the at least one additional thrust producing unit being preferably accommodated in a wing-independent shrouding.